Fireplaces have been used in homes over the years for providing heat as well as to provide a desired ambience. While firewood has been the primary fuel for burning in fireplaces, there is an increasing demand for artificial fire logs. These logs are easier to purchase and store, provide better Btu/lb value than wood, are easier to light, safer to use with virtually no maintenance during burning, and can be used to build fires of a known duration.
Various types of artificial fire logs are known and have been formulated to act as a substitute for natural firewood and are designed for use in fireplaces. Typically, artificial fire logs are made by mixing a material, usually particles of cellulosic origin, with a combustible binder. Wood particles and other cellulosic-containing materials are often used as the material. Various types of inexpensive waxes and related petroleum derived products are commonly used as the binders for the particles in the artificial fire logs. The binder functions to hold the fire log in a desired shape and aids in the combustion process, since it commonly provides a significant portion of the fire log's fuel value during the combustion of the fire log in a fireplace or other suitable combustion location.
Generally, artificial fire logs are formed by extruding the mixture through a bore extrusion die wherein the material and binder as well as any other materials incorporated therein are molded or extruded into an elongated form that resembles a piece of natural wood. The extruded product is cut into predetermined lengths that are sized to fit in a home fireplace and provide a predictable burn time. The elongated flammable bodies (also know as artificial fire logs) formed by this process are usually placed in a protective outer wrapper or sheath for sale, although this is optional and depends on the aesthetics of merchandizing and sale and the materials selected to form the artificial fire logs.
These artificial fire logs are typically marketed for sale to residential homeowners for use in a home fireplace to provide heat and an attractive fire that simulates the fire produced by a natural wood fire. In order to provide advantages over a natural wood fire, the artificial fire logs are formulated so that they can burn for a few hours without attending to the fire as would be required when burning natural wood. Also, artificial fire logs generally start much easier, burn cleaner and generate less ash compared to natural wood. In order to make the use of the artificial fuel log more attractive than use of natural wood, the fire log usually includes means for rapidly igniting it with a match which is applied to the outer wrapper. Further, since the artificial fire log is in many instances being used for the aesthetic enjoyment of a fire in social settings, any attributes that are similar to a traditional wood fire will enhance the pleasure of the products use and more closely simulate a traditional wood fire.
While existing artificial fire log can perform substantially as expected, there is now a growing demand for artificial fire logs that are made from non-petrochemical based materials that are renewable and yet perform substantially equivalent to an existing commercial fire log.